As wireless communication technology advances, two trends are clear: increasing numbers of users and a concomitant increased demand for capacity; and increasing sophistication and capabilities of User Equipment (UE), such as smartphones. To increase system capacity, multi-carrier solutions have become common. In multi-carrier systems (also known as carrier aggregation), a base station may provide wireless communication services to appropriately equipped UEs simultaneously on more than one carrier frequency.
One consequence of increasing UE sophistication, including large, high-resolution, color displays, is that users are increasingly choosing to view multimedia content (e.g., video programs with accompanying audio) on mobile UEs. Early solutions to this demand included Direct Video Broadcast (DVB) in Handheld (-H), Terrestrial (-T) and Satellite (-S) variants; MediaFLO; and Integrated Services Digital Broadcasting (ISDB-T). To address the demand for broadcast content in a system resource-efficient manner, making maximum use of the existing cellular infrastructure, Multimedia Broadcast Multicast Services (MBMS) was developed under the 3GPP framework for the Universal Mobile Telecommunications System (UMTS). MBMS is a specification for efficient point-to-multipoint delivery of multimedia content in 3GPP wireless communication networks. The Long Term Evolution (LTE) version is known as enhanced MBMS (eMBMS), or Multimedia Broadcast Single Frequency Network (MBSFN). MBMS type services are efficient because many UEs may be directed to tune to one carrier transmitting MBMS content rather than transmitting the multimedia content separately to each UE in a unicast (point-to-point) channel. Additionally, MBSFN allows a UE to increase signal gain by receiving the same broadcast signal from a plurality of transmitters.
In LTE, a base station may allocate time-frequency resources within each carrier—on a per-subframe basis—to either unicast or broadcast (eMBMS) service. Conventionally, this allocation is provisioned in advance, and is based on a network operators estimate of user interest in broadcast events (e.g., TV shows, sporting events, concerts, and the like). No mechanism is defined to facilitate the dynamic reallocation of downlink carrier subframes between unicast and broadcast functions. Accordingly, where the network operator's usage estimates are inaccurate, excess carrier resources may be dedicated to eMBMS transmissions, to which only a few UEs are subscribed, resulting in inefficient use of system resources.
The Background section of this document is provided to place embodiments of the present invention in technological and operational context, to assist those of skill in the art in understanding their scope and utility. Unless explicitly identified as such, no statement herein is admitted to be prior art merely by its inclusion in the Background section.